SETSOCKOPT(3XNET) X/Open Networking Services Library Functions
NAME
setsockopt - set the socket options
SYNOPSIS
cc [
flag... ]
file...
-lxnet [
library... ]
#include <sys/socket.h>
int setsockopt(
int socket,
int level,
int option_name,
const void*option_value,
socklen_t option_len);
DESCRIPTION
The
setsockopt() function sets the option specified by the
option_name argument, at the protocol level specified by the
level argument, to the
value pointed to by the
option_value argument for the socket associated
with the file descriptor specified by the
socket argument.
The
level argument specifies the protocol level at which the option
resides. To set options at the socket level, specify the
level argument
as
SOL_SOCKET. To set options at other levels, supply the appropriate
protocol number for the protocol controlling the option. For example, to
indicate that an option will be interpreted by the TCP (Transport Control
Protocol), set
level to the protocol number of TCP, as defined in
the<
netinet/in.h> header, or as determined by using
getprotobyname(3XNET).
The
option_name argument specifies a single option to set. The
option_name argument and any specified options are passed uninterpreted
to the appropriate protocol module for interpretations. The
<
sys/socket.h> header defines the socket level options. The options are
as follow
SO_DEBUG Turns on recording of debugging information. This
option enables or disables debugging in the underlying
protocol modules. This option takes an
int value. This
is a boolean option.
SO_BROADCAST Permits sending of broadcast messages, if this is
supported by the protocol. This option takes an
int value. This is a boolean option.
SO_REUSEADDR Specifies that the rules used in validating addresses
supplied to
bind(3XNET) should allow reuse of local
addresses, if this is supported by the protocol. This
option takes an
int value. This is a boolean option.
SO_KEEPALIVE Keeps connections active by enabling the periodic
transmission of messages, if this is supported by the
protocol. This option takes an
int value.
If the connected socket fails to respond to these
messages, the connection is broken and threads writing
to that socket are notified with a
SIGPIPE signal.
This is a boolean option.
SO_LINGER Lingers on a
close(2) if data is present. This option
controls the action taken when unsent messages queue on
a socket and
close(2) is performed. If
SO_LINGER is
set, the system blocks the process during
close(2) until
it can transmit the data or until the time expires. If
SO_LINGER is not specified, and
close(2) is issued, the
system handles the call in a way that allows the process
to continue as quickly as possible. This option takes a
linger structure, as defined in the <
sys/socket.h>
header, to specify the state of the option and linger
interval.
SO_OOBINLINE Leaves received out-of-band data (data marked urgent) in
line. This option takes an
int value. This is a boolean
option.
SO_SNDBUF Sets send buffer size. This option takes an
int value.
SO_RCVBUF Sets receive buffer size. This option takes an
int value.
SO_DONTROUTE Requests that outgoing messages bypass the standard
routing facilities. The destination must be on a
directly-connected network, and messages are directed to
the appropriate network interface according to the
destination address. The effect, if any, of this option
depends on what protocol is in use. This option takes an
int value. This is a boolean option.
SO_MAC_EXEMPT Sets the mandatory access control on the socket. A
socket that has this option enabled can communicate with
an unlabeled peer if the socket is in the global zone or
has a label that dominates the default label of the
peer. Otherwise, the socket must have a label that is
equal to the default label of the unlabeled peer.
SO_MAC_EXEMPT is a boolean option that is available only
when the system is configured with Trusted Extensions.
SO_ALLZONES Bypasses zone boundaries (privileged). This option
stores an
int value. This is a boolean option.
The
SO_ALLZONES option can be used to bypass zone
boundaries between shared-IP zones. Normally, the system
prevents a socket from being bound to an address that is
not assigned to the current zone. It also prevents a
socket that is bound to a wildcard address from
receiving traffic for other zones. However, some
daemons which run in the global zone might need to send
and receive traffic using addresses that belong to other
shared-IP zones. If set before a socket is bound,
SO_ALLZONES causes the socket to ignore zone boundaries
between shared-IP zones and permits the socket to be
bound to any address assigned to the shared-IP zones. If
the socket is bound to a wildcard address, it receives
traffic intended for all shared-IP zones and behaves as
if an equivalent socket were bound in each active
shared-IP zone. Applications that use the
SO_ALLZONES option to initiate connections or send datagram traffic
should specify the source address for outbound traffic
by binding to a specific address. There is no effect
from setting this option in an exclusive-IP zone.
Setting this option requires the
sys_net_config privilege. See
zones(7).
For boolean options,
0 indicates that the option is disabled and
1 indicates that the option is enabled.
Options at other protocol levels vary in format and name.
USAGE
The
setsockopt() function provides an application program with the means
to control socket behavior. An application program can use
setsockopt() to allocate buffer space, control timeouts, or permit socket data
broadcasts. The <
sys/socket.h> header defines the socket-level options
available to
setsockopt().
Options may exist at multiple protocol levels. The
SO_ options are always
present at the uppermost socket level.
RETURN VALUES
Upon successful completion,
setsockopt() returns
0. Otherwise,
-1 is
returned and
errno is set to indicate the error.
ERRORS
The
setsockopt() function will fail if:
EBADF The
socket argument is not a valid file descriptor.
EDOM The send and receive timeout values are too big to fit
into the timeout fields in the socket structure.
EFAULT The
option_value parameter can not be accessed or written.
EINVAL The specified option is invalid at the specified socket
level or the socket has been shut down.
EISCONN The socket is already connected, and a specified option
can not be set while the socket is connected.
ENOPROTOOPT The option is not supported by the protocol.
ENOTSOCK The
socket argument does not refer to a socket.
The
setsockopt() function may fail if:
ENOMEM There was insufficient memory available for the operation to
complete.
ENOBUFS Insufficient resources are available in the system to complete
the call.
ENOSR There were insufficient STREAMS resources available for the
operation to complete.
ATTRIBUTES
See
attributes(7) for descriptions of the following attributes:
+--------------------+-----------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+--------------------+-----------------+
|Interface Stability | Standard |
+--------------------+-----------------+
|MT-Level | MT-Safe |
+--------------------+-----------------+
SEE ALSO
bind(3XNET),
endprotoent(3XNET),
getsockopt(3XNET),
socket(3XNET),
attributes(7),
standards(7) January 21, 2007
SETSOCKOPT(3XNET)